2025/12/12 by Vivek Kumar Jha, Jha, Vivek Kumar, A. Sharma +5
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.2512.11961
openalex publication_date 2025/12/12 · openalex created_date 2025/12/17 · openalex updated_date 2026/07/28
We investigate optical variability across multiple timescales in a sample of radio-loud narrow-line Seyfert~1 (RL-NLSy1) galaxies, including γ-ray detected, γ-ray undetected, and non-jetted systems along with a comparison set of highly polarised core-dominated quasars (HPQs). Using Zwicky Transient Facility light curves, we measure fractional variability (F\rm var) and rest-frame structure functions (SFs) to test whether short-term jet-linked variability is reflected in long-term behaviour. γ-ray detected RL-NLSy1s and HPQs show steeply rising SFs, revealing strong long-term coherence despite modest F\rm var, consistent with Doppler-boosted synchrotron emission from relativistic jets. Non-jetted RL-NLSy1s exhibit the highest F\rm var but plateauing SFs, indicative of stochastic, disc-driven fluctuations lacking long-term coherence. γ-ray undetected RL-NLSy1s show the lowest F\rm var and nearly flat SFs, consistent with weak or absent jet activity across all timescales. Colour-magnitude trends show that jet-dominated sources exhibit redder-when-brighter behaviour, whereas disc-dominated systems exhibit bluer-when-brighter trends. These results show that SF-derived temporal coherence, rather than variability amplitude alone, is a promising diagnostic of jet dominance and orientation, offering a framework for interpreting AGN variability in forthcoming time-domain surveys.